Starting apparatus for internal-combustion engines



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1,353,876. Patentodfiopt. 28, 1920.

INVENTDR ATTURNEY UNITED STATES PATENT OFFICE.

HANS WEICHSEL. OF ST. LOUIS, MISSOURI. ASSIGNOB TO WAGNER ELECTRIC'MANU- FACTURING COMPANY, OF ST. LOUIS. MISSOURI. A CORPORATION OF MISSOURI.

STARTING APPARATUS FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Application filed May 23, 1919. Serial No. 299.318.

To (UMP/1mm? may concern:

Be it known that l. I'IANS Vnmnsnn, a citizen of Germany. residing at the city of St. Louis. State of Missouri. United States of America. have invented a certain new and useful Starting Apparatus for Inter- Tltll-CfilllllllStlOll Engines. of which the following is such a full. clear. and exact description as will enable any one skilled in the art. to which it appertains to make and use the same. reference being had-t0 the accompanying drawings. forming part of this specification. I

Some internal combustion engines. and particularly air cooled engines. will sometimes revolve backward. due to self ignition. This is particularly likely to occur when the engine. is being stopped. When such an engine is connected to n cranking motor by means of an overrunnhneclutch and reduction gearing. there is danger, upon its reversal. of the motor being driven at a speed which will wreck the machine although the power developed by the internal combustion engine under the circumstances named is not very great.

It is the object of my invention to overcome the above difficulty and in its broadest aspect the invention comprises means for providing a load resisting rotation of the engine in a direction opposed to its normal direction of rotation, and in the specific form herein illustrated I so organize the motor circuits that should the engine revolve backward the motor will act as a generator and thus prevent development of dangerously high speed.

In the accompanying drawing which illustrates one embodlment of my invention the armature 2 of the engine starting motor is connected to the engine shaft 6 by means of an overrunning clutch 5 diagrammatically illustrated. The motor is provided with a shunt field winding 4 and a series winding 3 and its circuits and connections with the starting battery 8 are controlled by the two-pole switch 7. In the position shown, which may be termed the off position, the switch 7 closes the armature circuit of the motor through the series winding 3 and the resistance 9 and connects the shunt Winding 4 in series with the battery 8. In the starting position of the switch,

the switch arms contact with points 10 and 11 and connect the battery to the armature in series with the field winding 3.

It will be understood that theswitch 7 is provided with any suitable means such as a spring 12, whereby when released by the operator it will assume the position shown in the drawing and will occupy this position at all times except when intentionally brought to the starting position for the purpose of cranking engine.

Back-firing of the engine usually takes place when the operator cuts off the ignition to stop the engine. Backward rotation of the engine produces the same relation between the clutch elements 5 as produced when the motor is cranking the en gine and the engine will therefore drive the motor, but since at such time the switch 7 closes the armature circuit over the series winding and the resistance 9 and also con nects the battery to the shunt winding 4 the rotation-of the motor in the backward direction will cause it to act as a generator thus constituting a brake preventing the comparatively small power developed by self-ignition from producing a speed high enough to cause mechanical injury to the motor.

It will be understood that since in the connections shown the motor is capable of self-excitation due to the fact that the armature circuit is closed through the series winding the separately excited shunt winding may be omitted but that this winding being constantly excited serves to immediately cause the production of current in the armature circuit. The shunt winding 4 may also be connected to the armature brushes instead of to the battery, if the advantages of separate excitation of this winding are deemed unnecessary. The resistance 9 serves to limit the outputof the motor, operating as a generator, and its use for such pur ose is well understood.

Iiiivin fully described my invention, what I c aim as new and desire to secure by Letters Patentof the United States is:

1. The combination with an internal combustion engine, a starting motor therefor, an overrunning clutch for connecting the motor to the engine, and means for short circuiting the motor to cause it to act as a Patented Sept. 28, 1920.

netator when the engine operates under its own power in the direction opposeitqto its normal direction of rotation.

2. The combination with an internal combustion engine, bf a series starting motor therefor, a battery, an overrunning clutch adapted to connect the motor to the engine when the motor operates to drive the engine, a switch for connecting the battery to the motor and means whereby said switch in its 011 position short-circuits the motor;

The combination with an internal combustion engine, of a series starting motor therefor provided with a shunt windmg, a battery, one-way clutch means adapted to connect the motor to the engine when the motor operates to drive the engine s switch for connecting the battery to the motor, and means whereby said switch in its off position short-circuits the motor and connects the battery to the shunt winding.

In testimony whereof, I have hereunto set my hand and affixed my seal.

HANS WEICHSEL. [1,. 8.] 

